Webster’s Revised Unabridged Dictionary · 1913
Freak
Freak (frēk), v. t. [imp. & p. p. Freaked (frēkt); p. pr. & vb. n. Freaking.] [Akin to OE. frakin, freken, freckle, Icel. freknur, pl., Sw. fräkne, Dan. fregne, Gr. περκνός dark-colored, Skr. pṛçni variegated. Cf. Freckle, Freck.] To variegate; to checker; to streak. [R.]
Freaked with many a mingled hue. Thomson.
Freak, n. [Prob. from OE. frek bold, AS. frec bold, greedly; akin to OHG. freh greedly, G. frech insolent, Icel. frekr greedy, Goth. faíhufriks avaricious.] A sudden causeless change or turn of the mind; a whim of fancy; a capricious prank; a vagary or caprice.
She is restless and peevish, and sometimes in a freak will instantly change her habitation. Spectator.
Syn. — Whim; caprice; folly; sport. See Whim.